Out-of-Sequence Error when running a Node  

  RSS

p00p
 p00p
(@p00p)
New Member
Joined:2 months  ago
Posts: 2
15/03/2018 2:23 pm  
Hey guys,

I have the following problem. When running a node@0.1.2 (.deb) at some point I start seeing the following message:


14:05:04.095 [scala-execution-context-global-23] ERROR main - Out-of-sequence message: UpstreamResponse(header {
sender {
id: "04e4822d2ffd40c585bf9b545608b9a6"
host: "172.17.0.3"
tcp_port: 30304
udp_port: 30304
}
timestamp: 1521119103806
seq: 116719
}
return_header {
timestamp: 1521119103898
seq: 175
}
upstream {
type_url: "type.googleapis.com/coop.rchain.comm.protocol.rchain.EncryptionHandshakeResponse"
value: "\n \336\236\333}{}\301\264\323[a\302\354\34457?\203C\310[xgM\255\374~\024o\210+O"
}

Any idea what might causing it ?


ReplyQuote
kirkwood
(@kirkwood)
New Member
Joined:4 months  ago
Posts: 3
15/03/2018 3:08 pm  

There are several reasons for that error message. The two most common are

  1. A late response to an earlier message sent by your node. Each request-response sequence initiated by your node has a timeout attached. When that timeout tolls, we no longer expect to receive a response. If a late response is received, that is indistinguishable from a message received out of order.
  2. A message to a stale entry in a remote's peer table. When a running node terminates, it broadcasts a message to all its peers to that effect. If a peer fails to receive that message (or if your node was terminated cruelly, so that no message was sent), then other nodes will continue to attempt to contact that dead node. One of those messages may be logged as you wrote as an out-of-sequence message.

Neither of these situations indicate a problem with  your currently running node, but they are useful for the development team when debugging the network overlay, and that is the reason they're logged.


p00p liked
ReplyQuote
p00p
 p00p
(@p00p)
New Member
Joined:2 months  ago
Posts: 2
15/03/2018 5:29 pm  

Thansk for the detailed reply @kirkwood .
If it doesn't represent a critical error can't it be marked as Warning?


ReplyQuote
radm
 radm
(@radm)
Member Admin
Joined:4 months  ago
Posts: 1
15/03/2018 7:09 pm  

Yes. It probably should not be marked as an error because out of order packets are common in any application. Developers will look at it and make changes as necessary for better notification information as well has handling of the UDP out of order if that is an issue. This is a downside to UDP where TCP handles ordering within its protocol. There is a cost in overhead for using TCP which is why UDP is used. For more information read the RFC https://tools.ietf.org/html/rfc768 or view a discussion like https://stackoverflow.com/questions/3745115/ensuring-packet-order-in-udp.


ReplyQuote
Kelly
(@kelly)
Member Admin
Joined:4 months  ago
Posts: 4
15/03/2018 7:31 pm  

Thanks for the feedback, @p00p. And thanks dev team for the support. To close the loop a bug has been filed (CORE-272) to change the message from 'error' to 'warning'.


ReplyQuote
  
Working

Please Login or Register